Jesper Neergaard

Inflation and instability of a polymeric membrane

Abstract We consider an axisymmetric polymeric membrane inflated by a uniform pressure difference acting across the membrane. The polymeric material is described by an arbitrary combination of a viscoelastic and a purely viscous component to the stress. Some viscoelastic materials described by a Mooney–Rivlin model show a monotone increasing pressure during inflation of a spherical membrane. These materials develop a homogeneous membrane thickness in agreement with the Considere–Pearson condition. Molecularly based models such as the neo-Hookean, Doi–Edwards or Tom–Pom model show a pressure maximum when inflated. Membranes described by these models develop a local thinning of the membrane which may lead to bursting in finite time.

Matrix Metalloproteinase Mediated Type I Collagen Degradation — An Independent Risk Factor for Mortality in Women

Chronic fibro-proliferative diseases are associated with nearly 45% of all deaths in the developed world. Matrix metalloproteinase (MMP) mediated remodeling of the extracellular matrix (ECM) plays an important role in disease development. Degradation of type I collagen is considered having a major role in this matter. C1M is a biomarker measuring type I collagen degradation fragments in blood. The aim of the current study was to investigate whether MMP mediated type I collagen degradation (C1M) was predictive of mortality in a large prospective cohort of Danish women aged 48–89 (n = 5855). Subjects with high serum C1M showed significant increased mortality. The adjusted three year HR was 2.02 [95% CI: 1.48–2.76] for all-cause mortality, 2.32 [95% CI: 1.51–3.56] for cancer and 1.77 [95% CI: 0.98–3.17] for cardiovascular diseases. The adjusted nine year HR was 1.50 [95% CI: 1.28–1.75] for all-cause mortality, 1.49 [95% CI: 1.16–1.90] for cancer and 1.69 [95% CI: 1.27–2.24] for cardiovascular diseases. High MMP-mediated type I collagen degradation was associated with increased mortality. Subjects with high C1M had a 2-fold increase in mortality compared to subjects with low levels of this collagen degradation product.

Metabolic Syndrome, Insulin Resistance, and Cognitive Dysfunction: Does Your Metabolic Profile Affect Your Brain?

Dementia and type 2 diabetes are both characterized by long prodromal phases, challenging the study of potential risk factors and their temporal relation. The progressive relation among metabolic syndrome, insulin resistance (IR), and dementia has recently been questioned, wherefore the aim of this study was to assess the potential association among these precursors of type 2 diabetes and cognitive dysfunction. Using data from the Prospective Epidemiological Risk Factor (PERF) Study (n = 2,103), a prospective study of elderly women in Denmark, we found that impaired fasting plasma glucose concentration was associated with 44% (9–91%) larger probability of cognitive dysfunction. In addition, subjects above the HOMA-IR threshold (HOMA-IR >2.6) had 47% (9–99%) larger odds of cognitive dysfunction. The associations could indicate that a significant proportion of dementia cases in women is likely to be preventable by effective prevention and control of the insulin homeostasis.

Metabolic syndrome and subsequent risk of type 2 diabetes and cardiovascular disease in elderly women: Challenging the current definition

AbstractThe prognostic value of the metabolic syndrome (MetS) is believed to vary with age. With an elderly population expecting to triple by 2060, it is important to evaluate the validity of MetS in this age group. We examined the association of MetS risk factors with later risk of type 2 diabetes (T2DM) and cardiovascular disease (CVD) in elderly Caucasian women. We further investigated if stratification of individuals not defined with MetS would add predictive power in defining future disease prevalence of individuals with MetS.The Prospective Epidemiological Risk Factor Study, a community-based cohort study, followed 3905 Danish women since 2000 (age: 70.1 ± 6.5) with no previous diagnosis of T2DM or CVD, holding all measurements used for MetS definition; central obesity, hypertension, hyperlipidemia, and hyperglycemia combined with register-based follow-up information.Elderly women with defined MetS presented a 6.3-fold increased risk of T2DM (95% confidence interval: [3.74–10.50]) and 1.7-fold increased risk of CVD (1.44–2.05) compared to women with no MetS risk factors. Subdividing the control group without defined MetS revealed that both centrally obese controls and controls holding other MetS risk factors also had increased risk of T2DM (hazard ratio (HR) = 2.21 [1.25–3.93] and HR = 1.75 [1.04–2.96]) and CVD (HR = 1.51 [1.25–1.83] and HR = 1.36 [1.15–1.60]) when compared to controls with no MetS risk factors.MetS in elderly Caucasian women increased risk of future T2DM and CVD. While not defined with MetS, women holding only some risk factors for MetS were also at increased risk of T2DM or CVD compared to women with no MetS risk factors.

Late-Life Risk Factors for All-Cause Dementia and Differential Dementia Diagnoses in Women: A Prospective Cohort Study.

AbstractSince the first evidence of a decline in dementia incidence was reported in 2011, the focus on modifiable risk factors has increased. The possibility of risk factor intervention as a prevention strategy has been widely discussed; however, further evidence in relation to risk factors is still needed.The Prospective Epidemiologic Risk Factor (PERF I) study was an observational prospective study of postmenopausal Danish women who were initially examined between 1999 and 2001 (n = 5855). Follow-up data on diagnosis and survival as of December 31, 2014 was retrieved from the National Danish Patient Registry and the National Danish Causes of Death Registry. Cox proportional hazards regression model was applied to calculate adjusted hazard ratios (HR) for selected risk factors for dementia.Of 5512 eligible subjects, 592 developed dementia within the follow-up period of maximum 15 years. The independent factors associated with increased risk of all-cause dementia were depression (HR = 1.75 [95% CI 1.32–2.34]) and impaired fasting glucose levels. A dose–response relationship was observed between fasting glucose level and risk of dementia with HRs of 1.25 [1.05–1.49] and 1.45 [1.03–2.06] for impaired (5.6–6.9 mmol/L) and hyperglycemic (≥7.0 mmol/L) glucose levels, respectively. The factors associated with a decreased risk of dementia were overweight in late-life (HR = 0.75 [0. 62–0.89]) and physical activity at least once weekly (HR = 0.77 [0.61–0.96]).The identified risk factors for dementia in women in late-life are all considered modifiable. This supports the notion that prevention strategies may improve the poor future prospects for dementias in the ageing population.

Excessive matrix metalloprotease-mediated degradation of interstitial tissue (type I collagen) independently predicts short-term survival in an observational study of postmenopausal women diagnosed with cancer

Extensive tissue remodeling mediated by matrix metalloproteases (MMPs) is an important part of cancer. The aim of this study was to investigate whether serum biomarkers reflecting MMP-mediated degradation of type I collagen (C1M), type IV collagen (C4M) and citrullinated vimentin (VICM) were predictive of cancer-specific mortality. Between 1999 and 2001, 5855 Danish postmenopausal women participated in The Prospective Epidemiologic Risk Factor (PERF I) study. Demographics and serum samples were collected at enrolment. Cancer diagnosis, and cause and time of death were obtained from Danish registries. C1M, C4M and VICM were measured by ELISA. Hazard ratios (HR) and Kaplan-Meier curves were applied to assess mortality at 3 and 12 years of follow-up for women diagnosed with cancer within 3 years from blood sampling. Within 3 years from blood sampling, 250 women had been diagnosed with cancer. C1M and VICM were associated with survival over time at 3 years of follow-up. Only C1M was predictive of mortality at 3 years follow-up: the adjusted HR was 2.65 [95% CI: 1.08-6.51]. In conclusion, C1M and VICM are associated with survival in postmenopausal women with cancer, and C1M is an independent risk factor for cancer-specific mortality. Thus, quantification of tissue remodeling is important in cancer.Extensive tissue remodeling mediated by matrix metalloproteases (MMPs) is an important part of cancer. The aim of this study was to investigate whether serum biomarkers reflecting MMP-mediated degradation of type I collagen (C1M), type IV collagen (C4M) and citrullinated vimentin (VICM) were predictive of cancer-specific mortality. Between 1999 and 2001, 5855 Danish postmenopausal women participated in The Prospective Epidemiologic Risk Factor (PERF I) study. Demographics and serum samples were collected at enrolment. Cancer diagnosis, and cause and time of death were obtained from Danish registries. C1M, C4M and VICM were measured by ELISA. Hazard ratios (HR) and Kaplan-Meier curves were applied to assess mortality at 3 and 12 years of follow-up for women diagnosed with cancer within 3 years from blood sampling. Within 3 years from blood sampling, 250 women had been diagnosed with cancer. C1M and VICM were associated with survival over time at 3 years of follow-up. Only C1M was predictive of mortality at 3 years follow-up: the adjusted HR was 2.65 [95% CI: 1.08-6.51]. In conclusion, C1M and VICM are associated with survival in postmenopausal women with cancer, and C1M is an independent risk factor for cancer-specific mortality. Thus, quantification of tissue remodeling is important in cancer.

Remodeling of the Tumor Microenvironment Predicts Increased Risk of Cancer in Postmenopausal Women: The Prospective Epidemiologic Risk Factor (PERF I) Study

Background: An altered tumor microenvironment is one of the earliest signs of cancer and an important driver of the disease. We have seen previously that biomarkers reflecting tumor microenvironment modifications, such as matrix metalloproteinase (MMP)-degraded type 1 collagen (C1M), MMP-degraded type IV collagen (C4M), and citrullinated and MMP-degraded vimentin (VICM), were higher in the serum of cancer patients than in healthy controls. However, it is not known if these biomarkers could predict an increased risk of cancer. The aim of this study was to investigate whether C1M, C4M, and VICM were elevated prior to diagnosis of solid cancers in a large prospective study. Methods: Between 1999 and 2001, 5,855 postmenopausal Danish women ages 48 to 89 years enrolled in the Prospective Epidemiologic Risk Factor study. Baseline demographics and serum were collected at the time of registration. Follow up cancer diagnoses were obtained from the Danish Cancer Registry in 2014. Serum C1M, C4M, and VICM levels were measured by competitive ELISAs. Results: A total of 881 women were diagnosed with solid cancers after baseline. C1M, C4M, and VICM levels were significantly elevated in women diagnosed less than 1 year after baseline. C1M and VICM, but not C4M, were independent predictors of increased risk of cancer. Conclusion: C1M, C4M, and VICM are elevated prior to cancer diagnosis. C1M and VICM are both independent predictors of increased cancer risk. Impact: C1M and VICM are predictors for increased risk of cancer. Cancer Epidemiol Biomarkers Prev; 25(9); 1348–55. ©2016 AACR.

Matrix Metalloproteinase Mediated Type I Collagen Degradation is an Independent Predictor of Increased Risk of Acute Myocardial Infarction in Postmenopausal Women

Acute myocardial infarction (AMI) is often underdiagnosed in women. It is therefore of interest to identify biomarkers that indicate increased risk of AMI and thereby help clinicians to have additional focus on the difficult AMI diagnosis. Type I Collagen, a component of the cardiac extracellular matrix, is cleaved by matrix metalloproteinases (MMPs) generating the neo-epitope C1M. We investigated the association between serum-C1M and AMI and evaluated whether C1M is a prognostic marker for outcome following AMI. This study is based on The Prospective Epidemiological Risk Factor (PERF) Study including postmenopausal women. 316 out of 5,450 women developed AMI within the follow-up period (14 years, median). A multivariate Cox analysis assessed association between serum-C1M and AMI, and re-infaction or death subsequent to AMI. The risk of AMI increased by 18% (p = 0.03) when serum-C1M was doubled and women in the highest quartile had a 33% increased risk compared to those in the low quartiles (p = 0.025). Serum-C1M was, however not related to reinfarction or death subsequent to AMI. In this study C1M was be an independent risk factor for AMI. Measuring MMP degraded type I collagen could be useful for prediction of increased risk of AMI if replicated in other cohorts.

Objective Cognitive Impairment and Progression to Dementia in Women: The Prospective Epidemiological Risk Factor Study

BACKGROUND Identification of subjects with a progressive disease phenotype is an urgent need in the pharmaceutical industry where most of the recent clinical trials in Alzheimers disease have failed. OBJECTIVES The objective of this study was to identify subgroups of individuals with objective cognitive impairment (OCI), who were most likely to progress to dementia and to identify the risk factors associated with progression. DESIGN Prospective cohort study. SETTING Population-based. PARTICIPANTS 5,380 elderly women from Denmark. MEASUREMENTS The Short Blessed Test and a category fluency test with animal naming, was used to assess cognitive function, and to classify them into different groups of OCI. RESULTS OCI was identified in 852 subjects at baseline. The risk of dementia was elevated for OCI subjects as compared to subjects with normal cognition (HR 1.46[1.19-1.79]). The courses of OCI were studied in a sub-cohort who completed the cognitive assessment at both the baseline and the follow-up visit (n = 1,933). Of these subjects 203 had OCI at baseline. The multi-domain subtypes of OCI were associated with progressive OCI. Subjects most likely to progress were older, physically inactive, had a higher level of total cholesterol (>6.5 mmol/L) and had a history of depression as compared to subjects with a non-progressive course of OCI. CONCLUSIONS In this cohort we identified a risk profile associated with progression from OCI in older women. The degree of impairment at baseline was an important predictor of conversion to dementia, additionally several modifiable risk factors were associated with progression.

Modifiable risk factors promoting neurodegeneration is associated with two novel brain degradation markers measured in serum

&NA; There has been limited success with blood‐based biomarkers of neurodegeneration. One perceived reason is that blood has no direct contact to the brain. Recently developed blood‐based biomarkers of tau‐degradation have shown promise as potential tools for peripheral assessment of neurodegeneration; however, factors contributing to the levels of these in blood are poorly understood. Using multiple linear regression analysis in cross‐sectional data from an observational cohort (n = 5626), the aim was to examine which factors correlate to the serological levels of two novel biomarkers measuring truncated tau fragments (Tau‐A and Tau‐C) in serum. Platelets, albumin and several modifiable risk factors, including Body Mass Index, high density lipoprotein and white blood cell count were associated with the serum level of tau fragments. The factors associated with tau in serum may promote neurodegeneration and alter the permeability of the Blood Brain Barrier through chronic inflammation and vascular dysfunction. These data are of key importance for understanding the mechanism of release and subsequent peripheral processing of tau from the brain and will assist in the development of future blood‐based biomarkers. HighligthsThe biomarker levels were associated with several modifiable risk factors.The factors may promote neurodegeneration through inflammation or vascular dysfunction.Serum levels of Tau‐A and Tau‐C showed an inverse association with verbal fluency.